<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Document</title>
  </head>
  <body>
    <script>
      var myName = '小明';
      console.log(myName);  // 输出结果：小明
      myName = '小红';      // 更新变量的值
      console.log(myName);  // 输出结果：小红
    </script>
  </body>
</html>